Why in knife k is silent?

Answer 1

..................... cause if we pronounce knife as K-nife I mean with K not silent it will be improper and silent ⟨k⟩ occurs when the letter ⟨k⟩ occurs in a word but does not actually reflect the pronunciation of a voiceless velar plosive (/k/), or any sound for that matter. A silent ⟨k⟩ is quite common in the English language, most often preceding an ⟨n⟩ at the beginning of a word. There are rare exceptions to this rule; one example is Knoebels Grove located in Pennsylvania